Applying pressure on bosoms can suppress the growth of cancer cells, according to UC Berkeley researchers who say the discovery has enormous implications for the future of cancer research and treatment.

The research, presented on Dec. 17 at the annual meeting of the American Society for Cell Biology, built upon a previous discovery by Professor Mina Bissell of the Lawrence Berkeley National Laboratory that found cancer cells are not necessarily fated to grow into tumors and may respond to outside forces to some degree.

As part of the experiment, researchers grew mammary cells in culture chambers that emulated the environment in which a cancer cell might grow in a living person. The elastic chambers were then stretched out and later compressed, allowing scientists to see the effects of physical pressure on cells.

They discovered that such pressure alone can suppress the unrestrained growth of cancer cells, even if the genetic mutations that initially activated the cancer remained.

The effect of compression on cell growth that the team observed was a surprise, said Daniel Fletcher, a professor in the department of bioengineering and lead researcher on the study.

“We thought we might find that cancer cells don’t really care about forces on them and will grow anyway,” he said. “We were very surprised to find that compression would guide the cells into a more normal growth phenotype.”

Conducted jointly by Fletcher’s lab in the department of bioengineering and Bissell’s team at the Berkeley lab, the study was part of new efforts by the National Institutes of Health to combine physical science research with ongoing cancer research. As part of that effort, Fletcher said his lab is seeking to shed greater light on how “mechanical compression might be involved in tumor progression.”

Scientists say, however, that the research is still very basic. Fletcher said he hopes it will help them continue to “identify the underlying molecular mechanisms” that allow cancerous cells to grow.

“We are continuing this work, focusing on how gene expression might be changed by the compressive loads on these cells,” Fletcher said.

Sara Grossman is a News Editor. Contact her at sgrossman@dailycal.org.